As days go by, personal belongings and other items from the ship have been spotted further and further away, fuelling concerns that some victims of the ferry disaster may never be found.

One body was retrieved on Friday by a fishing vessel two miles away from the recovery site, and another was found over a mile away on Wednesday.

As a precaution, recovery workers have put rings of netting around the site.

Bedding materials from the ship were found as far as 20 miles from the disaster site on Friday.

It is one of South Korea's worst peacetime disasters, made all the more shocking by the loss of so many young lives.

Of those on board, 325 were students from the same high school in Ansan city, just south of Seoul.

Public anger has focused on the captain and crew members who abandoned the ship while hundreds were trapped inside, and on the authorities as more evidence emerges of lax safety standards and possible corruption among state regulators.

The captain and 14 of his crew have been arrested.

The Sewol's regular captain, who was off duty on the day of the accident, has told prosecutors that the ferry operator – Chonghaejin Marine Co – "brushed aside" repeated warnings that the 20-year-old ship had stability issues following a renovation in 2012.

Two Chonghaejin officials were arrested on Friday on charges of having the ferry overloaded well beyond its legal limit.